Because they are made of cardboard, mouth breather.

因为是硬纸板做的 蠢蛋。

A mouth breather looking at me, like (breathes heavily) , y'know.

一个靠嘴巴出气的家伙紧盯着我，像这样（喘粗气声）。

I was tripped by this mouth breather, Troy, okay?

我被特洛伊那蠢货绊了一跤？

I figured you'd have the face of a mouth breather.

我猜你就该长这幅傻模样。

Could be the critters had to stop being such mouth breathers and shift from using gills to using lungs, which freed their jaws to develop in new ways.

可能是这些生物不得不停止用嘴呼吸，从用腮转为用肺，让下颚得以解放从而以新方式发育。